Conventional image sensor package includes a sensor chip mounted on a chip carrier and electrically connected to the chip carrier via bonding wires, and a transparent cover for covering the sensor chip to allow light to be captured by the sensor chip through the transparent cover. The image sensor package can be used in various electronic devices such as digital still camera (DSC), digital video camera (DV), optical mouse, mobile phone, fingerprint recognizer and the like.
In order to effectively reduce the size of the image sensor package, the CSP (chip scale package) technology is employed to form a CSP sensor semiconductor device, which desirably has a size slightly larger than the sensor chip incorporated therein and is suitably applied to a miniaturized electronic device.
FIG. 1 shows a CSP sensor semiconductor device disclosed in U.S. Pat. No. 6,646,289. For fabricating the CSP sensor semiconductor device, an active surface of a sensor chip 11 during a wafer stage is covered with a glass member 12 for protecting a sensor region 18 of the sensor chip 11, and a non-active surface of the sensor chip 11 is applied with an epoxy layer 13 and a passivation layer 14 thereon. Then, an etching process is performed on the non-active surface of the sensor chip 11 to form a plurality of inclined openings 15 for exposing electrode pads 110 of the sensor chip 11. A patterned circuit layer 16 can subsequently be formed on sidewalls of the inclined openings 15 and is electrically connected to the electrode pads 10 of the sensor chip 11. A plurality of solder balls 17 are implanted on the circuit layer 16 and a singulation process is performed so as to complete the CSP sensor semiconductor device, such that the semiconductor device can be electrically connected to an external device via the solder balls 17.
However, in the foregoing semiconductor device, a contact position between the circuit layer on the sidewall of the inclined opening and the electrode pad of the sensor chip forms an acute angle, making stress easily concentrated on the contact position and thereby leading to circuit cracking and failure in electrical connection. Moreover, the semiconductor device is fabricated in the wafer stage, such that fabrication processes are complicated and the problem of known good die (KGD) cannot be effectively solved, thereby resulting in a great increase in the fabrication cost.
Therefore, the problem to be solved here is to provide a CSP sensor semiconductor device and a fabrication method thereof such that the semiconductor device can be cost-effectively fabricated and circuit cracking can be avoided.